A huge archive of documents from the Iraq war, released by WikiLeaks, shows a multitude of shortcomings with the military's reliance on private contractors. The contractors lacked coordination with coalition forces and often shot with little discrimination -- and few if any consequences -- at unarmed Iraqi civilians, Iraqi security forces, American troops and even other contractors, stirring public outrage.

The documents also portray the long history of tensions between Kurds and Arabs in the north of Iraq and reveal the fears of some American units about what might happen after American troops leave the country by the end of 2011.